Customer networks are networks established by individuals or companies for internal communication. Customer networks may include local area networks (LAN) or wide area networks (WAN) that comprise a plurality of subscriber devices, such as personal computers, laptops, workstations, personal digital assistants (PDAs), wireless devices, network-ready appliances, filer servers, print servers or other devices. The customer networks may meet customer-specific needs using a number of different communication protocols, such as Asynchronous Transfer Mode (ATM) protocol, Ethernet protocol, Bridged Ethernet protocol, frame relay protocols or other communication protocols. ATM and frame relay protocols, for example, are frequently used for transport of audio, video, and computer data between a source and destination device within a customer network. Such protocols may transfer information in fixed-length units, such as frames.
To transfer the frames, switches within a customer network create a fixed network path, referred to as a virtual circuit. The frames transmitted by a source device within the customer network travel along the virtual circuit created by the switches. A destination device receives the frames from the virtual circuit, and reassembles the information from the frames.
Another popular network technology is the Internet Protocol (IP) networking protocol in which information is divided into variable-length blocks called packets. In contrast to frame-based protocols, such as ATM and frame relay, IP-based networks individually route these packets, also referred to as datagrams, across the network from a source device to a destination device. In other words, unlike the virtual circuits within a customer network, each packet can take a different route from the source to the destination device within the IP network. The destination device reorders the packets upon receipt, extracts the information from the packets, and assembles the information into its original form.
In order to allow remote customer networks to communicate, IP-based communication techniques are being developed that relay frames through an IP network, such as the Internet. According to the techniques, a network service provider of the IP network can receive frames from one of the customer networks, encapsulate the frames within packets, and route the packets through the IP network to the other customer network.
The IP network may support both a widely implemented Internet Protocol version 4 (IPv4) and a proposed Internet Protocol version 6 (IPv6). IPv4 defines a limited global address space comprising 232 globally unique addresses, which have recently become scarce. IPv6 addresses the lack of available globally unique addresses by increasing the number of available globally unique addresses from 232 to 2128. Currently, a customer network requires a dual interface configuration in order to access both portions of the IP network. However, statically implementing a dual interface column on each virtual circuit of the customer network may waste network service provider resources by creating unnecessary IP interfaces.